what's the point of friendship?​

Answer:

n = 1.4

Explanation:

Given,

R1 = 18 cm, R2 = -18 cm

From lens makers formula

1/f = (n - 1)(1/18 + 1/18) = (n-1)/9

f = 9/(n-1)

Power, P = 1/f ( in m) = (n-1)/0.09

Now, this lens is in with conjunction with a concave mirror which then can be thought of as to be in conjunction with another thin lens

Power of concave mirror = P' = 1/f ( in m) = 2/R = 2/0.18 = 1/0.09

Net power of the combination = 2P + P' = 2(n-1)/0.09 + 1/0.09 = 1/0.05

n = 1.4

The total momentum of the block and putty prior to their collision is

(0.454 kg) (0 m/s) + (5.70 × 10⁻² kg) (8.99 m/s) ≈ 0.512 kg•m/s

and the total momentum after the collision is

(0.454 kg) v + (5.70 × 10⁻² kg) (-8.99 m/s)

where v is the velocity of the block. Momentum is conserved, so

(0.454 kg) v + (5.70 × 10⁻² kg) (-8.99 m/s) = 0.512 kg•m/s

==>   v ≈ 2.26 m/s

The total work done on the block by the spring as it gets compressed by a distance x is equal to the change in the block's kinetic energy:

1/2 (25.0 N/m) x ² = 1/2 (0.454 kg) (2.26 m/s) - 0

==>   x ≈ 0.202 m ≈ 20.2 cm

Answer:

Breathing is the biological process of inhaling and exhaling of the gases between the cells and the environment. The mechanism of breathing involves various respiratory structures such as the windpipe, lungs and nose. Respiration, on the other hand, is a chemical process that takes place in the cell.

Explanation:

Answer:

B

Explanation:

Answer:

B

Explanation:

Answer:

Y = 17.75 x 10⁻³ m = 17.75 mm

Explanation:

Using Young's Double Slit formula below:

[tex]Y = \frac{\lambda L}{d}[/tex]

where,

Y = fringe separation = ?

λ = wavelength = 568 nm = 5.68 x 10⁻⁷ m

L = distance between slits and screen = 3.5 m

d = slit separation = 0.112 mm = 1.12 x 10⁻⁴ m

Therefore,

[tex]Y = \frac{(5.68\ x\ 10^{-7}\ m)(3.5\ m)}{1.12\ x\ 10^{-4}\ m}[/tex]

Y = 17.75 x 10⁻³ m = 17.75 mm

Answer:

a. Red and Orange

b. Yes, they are

Explanation:

a. This is because, since the yellow light is reflected back into the water, it undergoes total internal reflection and its wavelength in water is not long enough to allow it penetrate the water surface. Since the wavelength decreases from left to right, both the green and blue light have shorter wavelength than the yellow light, so they get reflected back. The red and orange lights are more likely to penetrate since they have longer wavelengths than the yellow light.

b. This is because the red and orange light have longer wavelengths and are thus more likely to penetrate the water surface and not get reflected back.

Answer:

ΔT = 4.058 10²⁰ [tex]\frac{S_o^2}{r^2 \ c_e}[/tex]

Explanation:

In this experiment the system can be approximated as a tube with one end open and the other closed.

The open end is where the ultrasound emitter is and the closed end where the limit between the tissue and the bone is, the length of the tube is L = 0.55 cm = 5.5 10⁻³ m

a node is formed at the closed end and a belly at the open end, so the resonance has the form

             λ = 4L                    1st harmonic

             λ = 4/3 L                third harmonic

             λ = 4/5 L                fifth harmonic

             λ = 4L / (2n + 1)     n = 0, 1, 2, (2n + 1)

This wave is a standing wave therefore energy density remains in place

                P = 1/2 ρ v (w S₀)²

angular velocity is related to frequency

               w = 2π f

we substitute

                E = P = 2π² ρ v f² S₀²

if this energy per unit area is transformed into heat

                E = m c_e DT

let's use the concept of density

                ρ = m / V

                m = ρ V

if there are no losses in the system

       ½ π² ρ v f² S₀² = ρ V c_e ΔT

       ΔT = [tex]\frac{\pi ^2 \ v \f^2 S_o^2}{2V \ c_e}[/tex]

When analyzing this expression the temperature increase is

* quadratic at the frequency and maximum amplitude of the wave

* proportional to the speed of the wave in the tissue

* inversely proportional to tissue volume

we can approximate the volume of the tissue to the volume of a cylinder tube

            V = π r² L

           ΔT = [tex]\frac{\pi \ v \ f^2 S_o^2 }{r^2 \ L \ c_e}[/tex]

we calculate

            ΔT = π 1450 (0.7 10⁶)² S₀² /( r² 5.5 10-3 c_e)

            ΔT = 4.058 10²⁰ [tex]\frac{S_o^2}{r^2 \ c_e}[/tex]

Answer:

Frequency = 1,550Hz

Explanation:

To solve this we can use the equation: [tex]f=\frac{v}{\lambda}[/tex]

(frequency = velocity/wavelength).

We are given the information that the wavelength is 22cm and the speed is 340m/s. The first step is to make sure everything is in the correct units (SI units), and to convert them if needed. The SI Units for velocity and wavelength are m/s and m respectively. This means we need to convert 22cm into meters, which we can do by dividing by 100, (as there are 100cm in a meter). 22/100 = 0.22m

Now we can substitute these values into the formula and calculate to solve:

[tex]f=\frac{340}{0.22} \\\\f=1545.454...[/tex]

Simplify to 3 significant figures:

f = 1,550Hz

(Which I believe is just below a G6 if you were interested)

Hope this helped!

Answer:

To pinpoint specific locations on Earth

Explanation:

The satellite has a full specific view of a specific area just like other satellites do. Satellites communicate together which also communicates with your GPS to give you an accurate location where you are or where you want to be. That is how satellites are used in GPS.

Hope this helps you out :)

Answer:

B

Explanation:

Answer:

Explanation:

a

Answer:

The depth of the diver is 28.01 m

Explanation:

Given;

density of the seawater, ρ = 1,015 kg/m³

standard sea level pressure, P₀ = 1.0 atm = 101,325 Pa

the final reading of her pressure, P₁ = 3.75 atm = 379968.75 Pa

acceleration due to gravity, g = 9.8 m/s²

Let the depth she was diving at the final pressure = h

This depth is calculated as;

P₁ = P₀  +  ρgh

P₁ - P₀ =  ρgh

[tex]h = \frac{ P_1 \ - \ P_o}{\rho g} = \frac{379968.75 \ - \ 101325}{1015 \ \times \ 9.8} = 28.01 \ m[/tex]

Therefore, the depth of the diver is 28.01 m

Answer:

yea im sorry

Explanation:

Answer:

..In a distance-time graph, the slope or gradient of the line is equal to the speed of the object. The steeper the line (and the greater the gradient) the faster the object is moving. Calculate the speed of the object represented by the green line in the graph, from 0 to 3 s.

d) steeper

D)Today

Answer:

L = 0.1379 m = 13.79 cm

Explanation:

The Rayleigh criterion establishes that two objects are separated when the maximum of diffraction for slits coincides with the minimum of the other point, therefore the expression for the diffraction

            a sin θ = m λ

the first zero occurs when m = 1

let's use trigonometry to find the angle

          tan θ = y / L

as in these experiments the angles are very small

          tan θ = sin θ /cos θ = sin θ

          sin θ = y / L

we substitute

          a y /L = λ

In the case of circular aperture the system must be solved in polar coordinates, for which a numerical constant is introduced

           a y / L = 1.22 λ

           L = a y / 1.22 λ

We search the magnitudes to the SI system

           a = 1.04 cm = 1.04 10⁻² m

           y = 9.09 10⁻⁶ m

           λ = 562 10⁻⁹ m

let's calculate

           L = [tex]\frac{1.04 \ 10^{-2} \ 9.09 \ 10^{-6} }{1.22 \ 562 \ 10^{-9} }[/tex]

           L = 1.379 10⁻¹ m

           L = 0.1379 m = 13.79 cm

Answer: Frequency

Explanation: Frequency is term which best describes how often a person exercises.

Answer:

frequency

Explanation:

I took the. test

Answer:

the following variables

Answer:

The answer is A

Explanation:

An insulator doesn't have to be a metal

<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3<3

Answer:

a substance which does not readily allow the passage of heat or sound.

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Answer:

The net torque will be "1366.33 Nm".

Explanation:

The given values are:

Length of ladder,

[tex]\tau_{242N} = 9.83 \ m[/tex]

then,

[tex]\tau=4.92[/tex]

Mass,

= 20.3 kg

Now,

The net torque will be:

⇒  [tex]\tau_{net}=\tau_{mg}+\tau_{242}[/tex]

On putting the given values, we get

⇒         [tex]=4.92\times (-mg)+9.83\times (+242)[/tex]

⇒         [tex]=4.92\times (-21\times 9.8)+9.83\times 242[/tex]

⇒         [tex]=-1012.53+2378.86[/tex]

⇒         [tex]=1366.33 \ Nm[/tex]

Explanation:

a) It will weigh less because of its distance from the block.

b) torque = W1×d1 = (10N)(0.25m) = 2.5 N-m

c) torque = W2×d2 = W2×(0.50m)

d) W2×d2 = W1×d1

W2 = (d1/d2)W1

= 5 N

Answer:

A/A₀ = 0.5106

Explanation:

To do this, we need to use several formulas and expressions. First, we need to know the period of time of the oscillator. This can be calculated using the following expression:

ω = 2π/T   (1)

But angular frequency (ω) can be also be calculated using:

ω = √(k/m)   (2)

Using (1) and (2), we can solve for the period T:

2π/T = √(k/m)    (mass in kg)

2π/T = √(130/0.360)

2π/T = √361.11

2π/T = 19.003

T = 2π/19.003 = 0.331 s

Now, the amplitude A at a time t, is:

A = x exp(-bt/2m)    (3)

At time 0, A = x. so A₀ = x

The problem states that we have 11 cycles respect to the initial amplitude, so expression (3) can be rewritten as:

A = x exp(-b(17t/2m))     using b as kg/s = 0.086 kg/s

Replacing the data we have:

A = x exp(-0.086(17*0.331)/2*0.36)

A = x exp(-0.086 * 7.815)

A = x exp(-0.6721)

A = 0.5106x    (4)

Now, doing the ratio with the innitial we have:

A / A₀ = 0.5106x / x

The ratio is:

Hope this helps

Answer:

the energy when it reaches the ground is equal to the energy when the spring is compressed.

Explanation:

For this comparison let's use the conservation of energy theorem.

Starting point. Compressed spring

         Em₀ = K_e = ½ k x²

Final point. When the box hits the ground

         Em_f = K = ½ m v²

since friction is zero, energy is conserved

          Em₀ = Em_f

          1 / 2k x² = ½ m v²

          v = [tex]\sqrt{ \frac{k}{m} }[/tex]     x

Therefore, the energy when it reaches the ground is equal to the energy when the spring is compressed.

Based on the law of conservation of energy, the elastic potential energy of the system when the spring is fully compressed is equal to the kinetic energy of the system at the moment immediately before the box hits the ground.

The energy in a compressed spring is elastic potential energy given by the formula:

where

The kinetic energy of a body is the energy the body the has due to it's motion.

Kinetic energy, KE, is givenby the formula below:

From the law of conservation of energy, the total energy in a closed system is conserved.

Based on this law, all the energy in the compressed spring is converted to the kinetic energy of the box just before it reaches the ground.

Therefore, the elastic potential energy of the system when the spring is fully compressed is equal to the kinetic energy of the system at the moment immediately before the box hits the ground.

Learn more about conservation of energy at: https://brainly.com/question/381281

Answer:

Explanation:

cross sectional area A = 40 cm² = 40 x 10⁻⁴ m² , n = 40 , Magnetic field B = 2 T . Current = I .

Maximum torque = 2 x 10⁻⁶ Nm

Value of maximum torque = n B A I .

n B A I = 2 x 10⁻⁶ Nm

40 x 2 x 40 x 10⁻⁴  I =  2 x 10⁻⁶ Nm

.32 I  = 2 x 10⁻⁶ Nm

I = 2  x 10⁻⁶ / 32 x 10⁻²

= .0625 x 10⁻⁴

= 6.25 x 10⁻⁶

= 6.25 μ A .

b )

Work done in rotating a coil = n B A I ( cos θ₂ - cosθ₁ )

= n B A I ( cos θ₂ - cosθ₁ )

= 2 x 10⁻⁶ ( cos 180 - cos θ )

= 2 x 10⁻⁶ ( -1  - cos θ )

= - 2 x 10⁻⁶ ( 1  + cos θ ) J .

Answer:

the force of the friction is A-0.52

Answer:

1) 392 joules

2) 625,000 joules

3) 156,800 joules

Explanation:

Gravitational potential energy = mgh. m = mass in kg, g = acceleration due to gravity and h = height in meters.

Kinetic energy = 1/2(m)(v)^2, m = mass in kg, v = velocity in meters per second

1) P.E = 2 x 9.8 x 20 = 392 joules

2) K.E = 1/2 x 2000 x (25)^2 = 625,000 joules

3) P.E = 80 x 9.8 x 200 = 156,800 joules

Answer:

[tex]1)\:392\:\text{J}\:(400\:\text{J with one significant figure)},\\2)\:625,000\:\text{J}\:(600,000\:\text{J with one significant figure)},\\3)\:156,800\:\text{J}\:(200,000\:\text{J with one significant figure)},[/tex]

Explanation:

1. The potential energy of an object is given by [tex]PE=mgh[/tex]. Substituting given values, we have:

[tex]PE=2\cdot 9.8\cdot 20=\boxed{392\:\text{J}}[/tex]

2. The kinetic energy of an object is given by [tex]KE=\frac{1}{2}mv^2[/tex]. Substituting given values, we have:

[tex]KE=\frac{1}{2}\cdot 2000\cdot 25^2 =\boxed{625,000\: \text{J}}[/tex]

3. 1. The potential energy of an object is given by [tex]PE=mgh[/tex]. Substituting given values, we have:

[tex]PE=80\cdot 9.8\cdot 200=\boxed{156,800\:\text{J}}[/tex]

Answer:

The wavelength will be "1.182 μm".

Explanation:

The given values are:

Wavelength

[tex]\lambda=591 \ nm[/tex]

or,

  [tex]=591\times 10^-9 \ m[/tex]

Distance,

[tex]d = 3.00 m[/tex]

[tex]n = 1[/tex]

Distance of fringe from center,

[tex]y = 4.84 \ mm[/tex]

We have to find the wavelength of first order dark fringe,

[tex]\lambda = ?[/tex]

As we know,

⇒ [tex]y_{bright} =\frac{1\times \lambda\times L}{d}[/tex]

On putting the given values in the formula, we get

   [tex]0.00484=\frac{1\times (591\times 10^{-9})\times 3}{d}[/tex]          

On applying the cross multiplication, we get

   [tex]\lambda = \frac{0.00484\times 000036632}{0.5\times 3}[/tex]

      [tex]=1182\times 10^{-9}[/tex]

or,

      [tex]=1.182 \ \mu m[/tex]    

Answer:

A quick return motion mechanism is used in the shaper and slotter machine in which the circular motion is converted into reciprocating motion so that the slider moves forward and backwards. In the forward direction, the cutting process occurs while in return there is no such cutting.

Answer:

[tex]n=1.56\times 10^{17}[/tex] electrons

Explanation:

Given that,

Total charge = 9 mC = 0.009 C

0.009 C of charge passes through a wire in 3.6 s.

Let q' is the charge that passes through it in 10 s.

So,

[tex]\dfrac{0.009 }{3.6}=\dfrac{q'}{10}\\\\q'=\dfrac{0.009 \times 10}{3.6}\\\\q'=0.025\ C[/tex]

We know that,

q = ne

Where

n is the number of electrons

So,

[tex]n=\dfrac{q}{e}\\\\n=\dfrac{0.025}{1.6\times 10^{-19}}\\\\n=1.56\times 10^{17}[/tex]

So, [tex]1.56\times 10^{17}[/tex]electrons must pass through the cross-sectional area.

Answer:

A) the magnetic field and the direction of motion must be perpendicular

For a current to be induced in a wire passing through a magnetic field, the magnetic field and the direction of motion must be perpendicular. The correct option is A.

The magnetic field is the region of space where another object experiences magnetic force and the current is induced in it.

According to the Fleming's right hand rule, the direction of motion, magnetic force and magnetic field are mutually perpendicular.

Thus, the correct option is A.

Learn more about magnetic field.

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